This text is a contribution to a series of Think Pieces written by the DEMAND Centre. Originally posted on September 5, 2016, here.

by Sanneke Kloppenburg, Robin Smale & Nick Verkade

The rise of renewable energy generated by wind turbines and PV poses challenges to the balancing of supply and demand of electricity. Solar panels only generate energy during day time, whereas a peak in consumption takes place in the evening. Storage of renewable energy near to their decentralized sources, at the domestic or local level, is increasingly seen as a solution to this problem. Rapid developments in battery technologies have even led some to claim that we are at the brink of a ‘storage revolution’ that may change the way householders and institutional actors engage with energy in fundamental ways. An important question then becomes how storage at household or community level may transform domestic energy practices and how it may lead to changes in the socio-material organisation of the future electricity system. In this short think piece we focus on questions and issues around the role of households in decentralised electricity storage. What types of storage models and services are emerging, what roles and practices for householders are implicated in these, and with what (potential) empowering effects for households?

This think piece is based on interviews we conducted with and documents we gathered from battery companies, storage consultants and experts, NGOs, and local governments. The fieldwork activities took place in the course of a multi-week relay research project across the UK as part of our DEMAND visiting fellowship in Spring 2016.

Different storage modes

First of all, storage can refer to both electricity and heat, and can use many different ‘energy nexuses’ at the domestic level. When we restrict our analysis to electricity storage, it still comes in many different shapes and forms: electricity storage can be integrated into the centralized grid at the household, neighbourhood, or national level, but it could also enable decentralized energy grids and facilitate the energy independence of communities. In more conceptual terms, different storage modes – defined as combinations of storage technologies and forms of social organisation (Walker and Cass 2007) – are currently emerging. Each storage mode entails a different distribution of tasks and responsibilities between householders and system actors (e.g. grid operators, intermediaries) and between humans and technologies (e.g. automation) and brings along particular ways of distributing costs and benefits. Storage modes may for example be more individualized or shared, public or private, more or less automated, and grid-service-centred or autonomy-centred.

Functions and values

Decentralized storage is currently positioned in the market as a tool for householders to self-consume solar energy as an alternative to selling it at the feed-in tariff; it appeals to consumers who value local energy autonomy and resilience. However, many actors for different reasons recognize the public value of domestic energy storage in facilitating the renewable energy transition, and form consortia to organize pilot projects. For distribution system operators (DSOs), domestic storage is an opportunity to increase much-needed demand-side flexibility, through enhanced peak-shaving and self-consumption; for NGOs, such as the Low Carbon Hub, domestic storage can play a key role in organizing locally sustainable, technologically and economically resilient energy communities; and market actors, such as battery hard- and software developer Moixa, are keen to supply storage products and services and partner up with (local) government to meet societal demand and expand their market. In other words, domestic storage has numerous functions for different actors. The various sought-after functions and values of domestic storage are reflected in different storage modes – each with their own implications for emerging energy practices, (new) social relations, and, ultimately, householder empowerment for sustainability.

Emerging energy (management) practices

One way to start analysing householders’ engagement in different storage modes is to identify the emerging energy practices around storage and the role of householders in these. In the specific technical and organisational design of storage systems and models, end-users are assigned particular roles that may or may not fit with their actual practices, preferences and needs. Storage modes afford (new) energy practices such as charging, discharging, and the exchanging, trading, monitoring and self-consuming of stored energy. Other practices that emerge around storage are installation and maintenance of the battery system, and the management of the battery charging strategy. Many of the more traditional forms of energy storage at household level, such as the stacking of wood and the storing of coal in coal houses, require physical abilities and planning skills (see Jalas and Rinkinen 2016), but what would be the type of competences and skills required from householders in the context of emerging practices around energy storage in batteries?

We observed that in real-world experiments by battery system companies and grid operator pilot projects, the emerging practices are often automated or carried out by third parties such as grid operators or intermediary organisations. Household storage systems may for example include elaborate Home Energy Management Systems, with algorithms that afford making predictions on the basis of consumption profiles and weather forecast to optimise ‘battery strategies’ (charging, selling, feeding in). Algorithms here act as mediators between past and future practices. Fully automated household storage systems may in addition eliminate the incentive for households to respond to time-of-day flexible tariffs through time-shifting their energy demand (automated instead of active demand-response). When managed by third party algorithms, domestic storage is expected to not only work for the householder, but also attend to short-notice grid management needs by enhancing flexibility in domestic energy demand. Discussions about householder empowerment centred around ownership of the devices, (public) investment, and flows of benefits to consumers; interviewees were mostly sceptical of greater end-user control in the operation of domestic storage, due to the (perceived) complexity of storage and timing principles and disinterest of householders.

Emerging energy communities

A storage mode may also entail new linkages between (formerly) spatiotemporally dispersed practices of consuming and producing energy through the making of new energy communities. In some of the pilot projects we studied this took the form of a local community of battery system owners around a substation, entwined with rationalities around consuming and producing energy locally, or providing grid services. But such communities need not necessarily be related to existing spatialities. Some storage modes include a virtual energy community. The German ‘sonnenCommunity’, for example, connects distributed individual battery system owners to form a ‘virtual energy community’ in which members all around Germany can share self-generated electricity, thereby bypassing traditional energy companies. The ‘sonnenCommunity’ example represents a different rationality of community and eco-sustainability, one facilitated by ‘labelled green electrons’ which can be shared among ‘virtual community’ members – which is different from the well-known local energy communities prevalent now in Europe.

Empowering households?

Because householder engagement in decentralised storage can take many different forms, the question of how decentralised storage could empower and benefit households cannot be easily answered. It seems that in existing business models for small-scale storage the emphasis is often on economic benefits, while at the same time the storage system remains a ‘black-box’ for the user with little possibilities to adjust settings or influence charging strategies. In order to develop models and services that empower and benefit citizens, alternative business models for storage should be considered: for example, some householders may favour business models that are based on other values than economic benefits (e.g. community, self-consumption, eco). This could include the availability of different algorithms for charging/discharging of the battery based on other values (eco, or grid services), and, related to this, alternative ways of visualising benefits for users via an energy management platform. For example, the home energy management display given to participants of Dutch smart grid pilot Your Energy Moment, visualises environmental benefits as well as economic benefits.

It is also important to consider how a particular storage mode interacts with existing socio-economic inequalities. Currently, household storage systems are mostly sold to (more affluent) PV owners: as feed-in tariffs are gradually phased out, storage enables self-consumption of solar power. If storage-enabled self-consumption leads to the ‘islanding’ of affluent households and energy communities, more grid management costs fall on the remaining on-grid households. There are also indications that fuel poor homes may struggle more with demand-response to time-of-day energy tariffs; automated storage systems could ensure that demand time-shifting cost-savings also flow to households less capable or willing to participate in demand-side flexibility, or renewable energy generation. A central remaining question in ongoing projects such as ERIC and SWELL in Oxfordshire, is how domestic energy storage can be organized in a way that benefits flow back to the entire community, and especially to homes in fuel poverty.

In order to foster storage modes and services that empower and benefit citizens, end-users should be given the chance to experiment in pilot projects with different levels of rights and responsibilities regarding the management and use of local storage devices. Such an approach would recognize that the ‘storage revolution’ should not just be seen in technical terms, but also as an experiment with new ways of relating to energy and new forms of social organisation of energy production and consumption. Understanding how domestic energy storage may empower householders to lead low-carbon lifestyles requires the study of various emerging storage modes in which householders are entrusted or assigned different roles and responsibilities.